Development and Survival of Immature Mosquitoes (Diptera: Culicidae) in Philippine Rice Fields1

Abstract

Development and survival of immature mosquitoes were studied in rice fields on Palawan and Luzon islands in the Philippines. Adding food to rice-field water shortened the 4thinstar larval period but did not influence survival of Culex vishnui or Anopheles peditaeniatus reared in predator-free cages. Survival from larval hatch to adult emergence was 50.0–88.8% in predator-free cages set in rice fields. In the same rice fields, survival of natural populations exposed to predators was as low as 0.0–1.8% for Culex (Culex) and 1.1–4.7% for Anopheles. Predators killed 48.7–87.0% of hatched larvae before adult emergence. Mortality resulting from predation was higher in rice fields where aquatic insect predators were more abundant. Coelomomyces infection was a minor mortality factor and was recognized only for Anopheles vagus vagus. Intraspecific mortality factors were not recognized.